Ford Electric Ranger 2001 Manual page 298

412-02-4
DIAGNOSIS AND TESTING (Continued)
• DTC C1780 Temperature Select Failure
— The interface adapter assembly (IAA) module
monitors the temperature control signal from
the climate control temperature control
potentiometer. The IAA module sets DTC
C1780 if it detects the temperature command
to be greater than 4.95 volts or less than 0.05
volts for more than 30 seconds.
• DTC B1857 Climate Control On/Off Switch
Failure
— The interface adapter assembly (IAA) module
monitors the A/C present, system on, A/C on,
and recirculation signals to determine if there
is a climate control on/off switch failure. The
IAA module determines if the vehicle is
equipped with A/C by detecting an A/C
present signal from the A/C inverter motor
controller (IMC). The IAA module receives
the A/C on and system on signals from the
mode select switch and the recirculation signal
from the fresh/recirculation select switch. The
IAA module sets DTC B1857 if it detects an
invalid combination of the inputs for more
than 45 seconds.
• DTC U2015 Signal Link Fault (Non SCP)
— During the 5 seconds after receiving 12-volt
power from the interface adapter assembly
(IAA) module, the positive temperature
coefficient (PTC) switching module carries out
a power on self test (POST) and outputs a 1.5
second-long pulse signal over the
overtemperature fault line to the IAA module
to indicate it passed the POST. If the IAA
module does not receive this pulse, it will turn
off the 12-volt power for 0.5 seconds and
retry up to 3 times per ignition key cycle. If
all three attempts at powering the PTC
switching module fail, the IAA module
assumes the PTC switching module failed its
POST and sets DTC U2015. The IAA module
also sets DTC U2015 if the PTC switching
module detects an internal short and pulls the
short fault line to the IAA module low (0
volts).
Heating and Ventilation
• DTC B2513 Blower (Fan) Circuit Failure
— The interface adapter assembly (IAA) module
provides the pulse width modulation (PWM)
control signal to the variable blower controller
(VBC) and monitors the VBC feedback. The
VBC contains an internal transistor relay that
is used to drive the blower motor at high
speed. The IAA module sets DTC B2513 if
the blower motor relay is closed, the VBC
internal relay is not closed or the VBC control
signal is greater than 1%, and the VBC
feedback is less than 1 volt for more than 30
seconds. If DTC B2513 is set and the blower
motor operates, the VBC has failed. If DTC
B2513 is set and the blower motor does not
operate, but the coolant pump does, the blower
motor circuit has failed. If DTC B2513 is set
and the blower motor and coolant pump do
not operate, the blower motor/coolant pump
relay circuit has failed.
• DTC B2514 Blower (Fan) Circuit Short to Vbat
— The interface adapter assembly (IAA) module
provides the pulse width modulation (PWM)
control signal to the variable blower controller
(VBC) and monitors the VBC feedback. The
IAA module sets DTC B2514 if the blower
motor relay is open and the VBC feedback is
greater than the auxiliary battery voltage
minus 1 volt for more than 30 seconds.
• DTC B2515 Heater Blower Relay Circuit Failure
— The interface adapter assembly (IAA) module
provides the pulse width modulation (PWM)
control signal to the variable blower controller
(VBC) and monitors the VBC feedback. The
VBC contains an internal transistor relay that
is used to drive the blower motor at high
speed. The IAA module sets DTC B2515 if
the VBC internal transistor relay is closed and
the VBC feedback is greater than 2 volts for
more than 30 seconds.
412-02-4
2001 Ranger EV, 01/2001